Search results
Results from the WOW.Com Content Network
In polymer chemistry photo-oxidation (sometimes: oxidative photodegradation) is the degradation of a polymer surface due to the combined action of light and oxygen. [1] It is the most significant factor in the weathering of plastics. [2] Photo-oxidation causes the polymer chains to break (chain scission), resulting in the material becoming ...
Polycarbonate. Polycarbonates (PC) are a group of thermoplastic polymers containing carbonate groups in their chemical structures. Polycarbonates used in engineering are strong, tough materials, and some grades are optically transparent. They are easily worked, molded, and thermoformed. Because of these properties, polycarbonates find many ...
Hindered amine light stabilizers (HALS) are chemical compounds containing an amine functional group that are used as stabilizers in plastics and polymers. [1] These compounds are typically derivatives of tetramethylpiperidine and are primarily used to protect the polymers from the effects of photo-oxidation; as opposed to other forms of polymer degradation such as ozonolysis.
Polymer degradation is the reduction in the physical properties of a polymer, such as strength, caused by changes in its chemical composition.Polymers and particularly plastics are subject to degradation at all stages of their product life cycle, including during their initial processing, use, disposal into the environment and recycling. [1]
Polymer stabilizers (British English: polymer stabilisers) are chemical additives which may be added to polymeric materials to inhibit or retard their degradation. Mainly they protect plastic and rubber products against heat, oxidation, and UV light. The biggest quantity of stabilizers is used for polyvinyl chloride (PVC), as the production and ...
Weather testing of polymers. Detail of the inside of SEPAP 12-24 Unit (4 lamps) Accelerated photo-ageing of polymers in SEPAP units is the controlled polymer degradation and polymer coating degradation under lab or natural conditions. The prediction of the ageing of plastic materials is a subject that concerns both users and manufacturers.
6mm Twinwall Polycarbonate Sheet. Twin-wall plastic, specifically twin-wall polycarbonate, is an extruded multi-wall polymer product created for applications where its strength, thermally insulative properties, and moderate cost are ideal. [1] Polycarbonate, which is most commonly formed through the reaction of Bisphenol A and Carbonyl Chloride ...
Photopolymer. A photopolymer or light-activated resin is a polymer that changes its properties when exposed to light, often in the ultraviolet or visible region of the electromagnetic spectrum. [1] These changes are often manifested structurally, for example hardening of the material occurs as a result of cross-linking when exposed to light.